The present invention relates generally to an improved ink-jet printer service method and system. More particularly, the invention concerns a mechanism that includes an improved automatic system for wiping and capping plural printheads that depends upon printer carriage motion and that utilizes uni-directional, separate wiping action for each printhead and capping of each printhead with a constant capping force.
Ink-jet printhead nozzles commonly become plugged with ink blobs or particulate therein, or otherwise contaminated with internal bubbles that prevent them from operating properly. Lower print quality and user complaints often result. Conventional service mechanisms typically provide for the spitting, wiping and capping of single printheads, frequently require operator intervention and often take the printer off-line for several seconds. Wiping an ink-jet printhead in two directions, or wiping multiple printheads with a single wiper surface, results in recontamination of a printhead during wiping or inter-printhead contamination.
Improved capping systems have been proposed that provide for constant-force, rather than constant-deflection, capping of plural printheads in ink-jet printers. One such capping system is described in my co-pending U.S. patent application Ser. No. 07/935,606, entitled "Ink-jet Printhead Cap Having Suspended Lip", which was filed Aug. 26, 1992, and which is commonly owned herewith. The disclosure of that co-pending patent application is incorporated herein by this reference.
Failure recovery methods and systems have been proposed that provide for the automatic recovery from a condition in a plural printhead ink-jet printer in which the printhead's nozzles become clogged with ink and particulate, wherein the method preferably includes capping the printheads, selectively priming and flushing a given printhead and then uncapping and wiping the printheads. One such method and system is described in my co-pending U.S. patent application Ser. No. 07/949,318, entitled "Automatic Failure Recovery for Ink-jet Printheads", which was filed concurrently herewith on Sep. 21, 1992, and which is commonly owned herewith. The disclosure of that co-pending patent application also is incorporated herein by this reference.
The invented method and apparatus preferably include a sled that is gimbal-mounted to a printer's chassis, the sled mounting plural pairs of caps and wipers for each of the printer's movable carriage-mounted printheads. The sled and the chassis are cam-coupled for controlled, relative movement therebetween. The sled and the carriage are also cam-coupled for controlled, relative movement therebetween. Movement of the carriage produces slight vertical and lateral movement of the sled out of its nominal position to place it in three primary positions relative to the carriage: an elevated position for capping the printheads, an intermediate position for wiping the printheads and a lowered position for free reciprocal movement of the carriage without interference between the printheads and either the caps or the wipers. Thus, a controller that includes only the printer's carriage drive motor provides printer servicing, including capping and wiping.
Preferably, capping is under the constant force imparted by the gimbal-mounted sled, which gimbal preferably takes the form of plural spring elements. Preferably, wiping is uni-directional, thereby avoiding recontamination of a printhead during a return swipe. Importantly, there is no permanent lock-out state of the method and apparatus from which printing would not resume without operator intervention. The preferred method involves uncapping the printheads, wiping the printheads uni-directionally, lowering the sled to its free position beneath the printheads, optionally re-wiping the printheads repeatedly, and returning the printheads to their capped position. During the wiping operation, one or more of the printheads also may be spitted to wet the corresponding wiper. The method and apparatus of the invention are compatible with automatic priming of selected ones of the plural printheads.